herdman



(N0 Model.) F E 2 Sheets-Sheet 1.

ELEVATOR Ptented May 19, 1896.

2 Sheets-Sheet 2.

(:No Model.)

P. E. HERDMAN.

V ELEVATOR. No. 560,208. Patented May 19, 1896.

ANDREW 8 GRAHAM.PHOT0-UTHO.WASHINUTUN.D c

UNTTED STATES PATENT GFFICE.

FRANK E. I-IERDMAN, OF INDIANAPOLIS, INDIANA.

ELEVATOR.

SPECIFICATION forming part of Letters Patent No. 560,208, dated May 19,1896.

Application filed June 21, 1893.

To all whom it may concern.-

Be it known that I, FRANK E. HERDMAN, a citizen of the United States,residing at In dianapolis, county of Marion, and State of Indiana, haveinvented a new and useful Improvement in Elevators, of which thefollowing is a full, clear, and exact description, reference being hadto the accompanyingdrawings, which form a part of this specification.

My invention has for its object the automatic stopping of an elevator atthe end of its travel, either up or down, and is particu larlyapplicable to elevators operated by a winding drum and ordinarilystopped by means of a friction-brake. The objection to the ordinaryfriction-brake is that by reason of its giving a certain definite amountof resistance to the further travel of the elevator the power cannot beproportioned to the speed of the elevator nor to the load in the car.The consequence is that if the load is heavy or the speed great the carwill travel a much greater distance than it would were the load light orthe car traveling slowly. Hence to prevent the possibility of the carstriking considerable leeway must be given to itthat is, thefriction-brake must be applied too long before the elevator reaches theend of its travel. My invention is designed to obviate this objection tothe friction-brake by using mechanism in connection with the windingdrumwhereby the car will be automatically stopped with certainty just beforeit reaches its extreme limit of movement independently of thefriction-brake and without regard to the load in the car or the speed ofits movement.

To carry out my invention, I use certain mechanism which I hereinafterparticularly describe, but which may be varied radically withoutdeparting from my invention, the essential feature of which is afluid-containing piston and cylinder to which is connected mechanismwhich is operated by the elevatorhoisting mechanism at a certain pointof its revolution to cause the piston to travel in the cylinder and bythe resistance of the fluid to the travel of the piston generally stopthe elevator.

I will now describe the mechanism which I prefer to use to carry out myinvention.

I do not illustrate the elevator -'car, the

Serial No. 478,352. (No model.)

power for revolving the drum-shat t, the stopping, starting, andreversing mechanism under the control of the operator in the car, northe connections between them and the drumshaft, as these embody manydifferent constructions well known to those familiar with elevatorconstruction and form no part of my invention.

In the drawings, Figure l is afront elevation of the winding-drum andmechanism connected therewith embodying my invention. Fig. 2 is a sideelevation of the same. Fig. 3 is a detached sectional view of cylindershown in Fig. 1. Fig. 4 is a View, same as Fig. 1, of modified form ofpiston-returning device. Fig. 5 is a sectional view of modified form ofcylinder. Fig. 6 is a section on the line sc :1: of Fig. 5.

Referring particularly to Figs. 1 and 2, N represents a portion of thebed-plate and supporting-frame of the drum. M is the drum; m, thedrum-shaft. On the drum-shaft is keyed the gear A, which meshes with thegear B, larger than the gear A. The gear 13 is keyed to the shaft I),mounted on a bearing on the bracket 7). The shaft 1) has also keyed toit the gear B, smaller than the gear B. The gear 13 meshes with the gear0, larger than the gear B. This gear 0 moves on a screw and has stops 0upon it, the purpose of which will be hereinafter explained. To thebearing carrying this gear 0 is pivoted the yoke E, which passes oneither side of said gear, as shown in Fig.2. To theyoke Eis attached thepiston-rod F of the piston F of the cylinder F. The cylinder F ispivoted to the bracket N at 'n, so as to permit its moving from side toside on its pivotal bearing.

Fig. 3 shows a section of the cylinder F.

observed that there is thus a passage formed from one side to the otherof the piston and that the said passage will be gradually cut off whenthe piston moves toward the end of To the framework is attached thecylinder.

This cylinder has aseries of holes f from one one end of each of thesprings G, which, at their other ends, are attached to an extension ofthe yoke E. (See Fig. 2.)

The operation of the above-described mechanism is as follows: As thedrum revolves, the gear A revolves, which, through the gears B and B,revolves the gear 0, which travels much more slowly than the drum. Inaddition to this axial revolution it travels from one end to the otherof the screw D, which forms its bearing. As it reaches the end of thescrew-thread, one of the projections c is brought in line with the yokeE and moves it in the direction in which the drum is traveling. Thearrangement of the gears and the length and pitch of the screw are suchthat the projection c engages the yoke E just before the car reaches itslimit of movement in one direction. The normal position of the yoke andpiston-rod is such that the pistonhead F is located centrally in thecylinder F. The yoke in its movement up or down carries with it thepiston-rod F. The piston-head F forces the fluid in the inner chamberthrough the apertures f into the outerchamher. As the piston movestoward the end of the cylinder, one aperture after another is cut off,and as the outlets for the contained fluid are gradually diminished theresistance of the contained fluid to the movement of the piston-head isgradually increased, and the rate of travel of the piston is graduallydiminished until when or just before it reaches the end of the cylinderits movement is stopped, thus stopping the stop 0, the gear 0, the drum,and the elevator-car. When the drum is traveling in the oppositedirection, the gear D also travels in an opposite direc tion on itsscrew-bearings, and as the car nears the end of its travel the otherprojection 0 comes in contact with the other side of the yoke E .andoperates the piston F in the other direction. versed, after being thusstopped, the stop 0 moves away from the yoke E, and the springs G act toreturn the piston to its central position. The check-valve at that endopens, which admits of an easy return.

It will be observed that the essential characteristic of my invention isthat there should be some mechanism (in this case the gears A B B C,screw D, projection c, and yoke E) between the piston and the drum,which is adapted at predetermined intervals in the drums revolution tocause the .piston to travel in the cylinder and gradually cut off thepassage from one side to the other of the piston. I

do not confine myself to the specific mechanism between the piston andthe drum shown and described, as it is obvious that other mechanism maybe substituted for that described without departing from the inventionas I have claimed it in my broader claims.

The cylinder may be constructed in many dilferent ways. Instead of theholes f a thin slot may be used. In Figs. 5 and G I have \Vhen theelevator is reshown front'and side views of a slot which answers thepurpose. F is the cylinder; f the slot, which, as will be seen, islargest at the central part of the cylinder and tapers toward each end,where it terminates. Vhen the piston commences to move, the avenue forthe escape of the contained fluid is large, but gradually diminishes asthe piston moves in the cylinder. This arrangement has the advantage ofcheapness over that hereinbefore described.

In place of the spring G for returning the piston to its centralposition other and positive means may be employed. In Fig. 4 I show afront view of another device for accomplishing this result. To the upperend of the piston-rod are attached the prongs F and F. c is one arm ofthe yoke E. (Shown in Figs. 1 and c is the stop. The prong F is adjustedso that the stop 0 just clears it every time it passes it. "When thestop 0 comes in contact with the yoke E and moves the yoke andpiston-rod upward, the prong F is moved upward with it and follows upthe stop 0. vVhen the drum revolves in the opposite direction, the stop0 immediately comes in contact with the projection F and moves it down,thereby returning the piston to its normal position. The prong F willact to return the piston-rod when the latter is at the opposite end ofthe cylinder to that just described. These prongs, of course, are bent,so that they will be on opposite sides of the gear-wheel C.

The arrangement of gears A, B, B, and C may be varied, as desired. Ifthe travel is short and the strain is not too great, the gears may be soarranged or multiplied that the gear G will not make more than onerevolution to the entire travel in one direction of the elevator. Insuch case the screw may be dispensed with, as the stops 0 would onlycome once in line with the yoke E. Under ordinary circumstances,especially if the travel of the car is great, it is difficult to arrangethe gears so that the gear 0 will make but one revolution, while thestrain upon it would be great. The advantage of the screw is that thegear may make several revolutions before the stop upon it operates thepistonrod, thus materially reducing the size and number of the gears andthe strain upon the mechanism.

For the fluid-containing-cylinder buifer may be substituted any of thewell-known types of spring-buffers, and I do not restrict myself, exceptwhere I particularly claim it, to a fluid-containing-cylinder buffer.This latter form of buifer is, however, preferable, its results inpractice being decidedly more satisfactory.

I have shown merely the application of my invention to a winding-drum,although it is obvious that when other elevator-hoisting mechanism issubstituted for the drum the invention is equally applicable thereto.

Having now fully described my invention, what I claim, and desire toprotect by Letters Patent, is-

1. In an elevator operated by a windingdrum, the combination with thedrum of the buffer, a connection between said buffer and the drum, agear-wheel revolved by the drumsliaft, a yoke connected with said pistonand extending on each side of said gear-wheel, and a projection on eachside of said gearwheel adapted to be brought in line with thecorresponding arm of the yoke to move said connection against saidbutter.

2. In an elevator operated by a windingdrum, the combination with thedrum of a buffer, a connection between said buffer and the drum, athreaded shaft operated by the d rum-shaft, a gear-wheel having itsbearing on said threaded shaft, a yoke connected with said piston andextending on each side of said gear-wheel, and a projection on each sideof said gear-wheel adapted to be brought in line with the correspondingarm of the yoke to move said connection against said buffer.

In an elevator operated by a windingdrum, the combination with the drumof a cylinder adapted to contain a fluid, apiston in said cylinder,there being a passage in said cylinder from one side to the other of thepiston-head, a gear-wheel revolved by the drum-shaft, a yoke connectedwith said piston and extending on each side of said gearwheel, and aprojection on each side of said gear-wheel adapted to be brought in linewith the corresponding arm of the yoke to move said yoke and the pistonin the cylinder and gradually cut off said passage.

4:. In an elevator operated by a windingdrum, the combination with thedrum, of a cylinder adapted to contain a fluid, a piston in saidcylinder, there being a passage in said cylinder, from one side to theother of the piston-head, a gear-wheel revolved by the drum-shaft, ayoke connected with said piston and extending on each side of saidgearwheel, and a projection on each side of said gear-wheel adapted tobe brought in line with the corresponding arm of the yoke to move saidyoke and the piston in the cylinder and gradually cut off said passage,and means to cause said piston to return to its normal position.

5. In an elevator operated by a windingdrum, the combination with thedrum, of a cylinder adapted to contain a fluid, a piston in saidcylinder, there being a passage in said cylinder from one side to theother of the piston-head, a threaded shaft operated by the drum-shaft, agear-wheel having its bearing on said threaded shaft, ayoke connectedwith said piston and extending on each side of said gear-wheel, and aprojection on each side of said gcar-wheel adapted to be brought in linewith the corresponding arm of the yoke to move said yoke and the pistonin the cylinder and gradually cut off said passage.

6. In an elevator operated by a windingdrum, the combination with thedrum, of a cylinder adapted to contain a fluid, a piston in saidcylinder, there being a passage in said cylinder from one side to theother of the piston-head, a threaded shaft operated by the drum-shaft, agear-wheel having its hearing on said threaded shaft, ayoke connectedwith said piston and extending on each side of said gear-wheel, and aprojection on each side of said gear-wheel adapted to be brought in linewith the corresponding arm of the yoke to move said yoke and the pistonin the cylinder and gradually cut oft said passage, and means to causesaid piston'to return to its normal position.

7. In an elevator operated by a windingdrum, the combination with thedrum of a cylinder adapted to contain a fluid, a piston in saidcylinder, there being a passage from one side to the other of thepiston, a wheel, a stop on said wheel, a connection between the wheeland the drum, and a device connected with the piston in line of movementof said step, whereby at a predetermined point in the drums revolutionthe stop is caused to engage said device and operate the piston,substantially as described.

8. In an elevator operated by a windingdrum, the combination with thedrum of a cylinder adapted to contain a fluid, a piston in saidcylinder, there being a passage from one side to the other of thepiston, a wheel, a stop on said wheel, a connection between the wheeland the drum, and a device connected with the piston in line of movementof said stop, whereby at a predetermined point in the drums revolutionthe stop is caused to engage said device and operate the piston, andmeans to cause said piston to return to its normal position.

9. In an elevator operated by a winding drum, the combination with thedrum, of a cylinder adapted to contain a fluid, a piston in saidcylinder, there being a passage in said cylinder from one side to theother of the piston-head, connection between said piston and the drum,and mechanism operated by said drum at predetermined points in itsrevolution to cause said piston to travel in said cylinder and graduallycut off said passage, substantially as described.

10. In an elevator operated by a windingdrum, the combination with thedrum of a cylinder adapted to contain a fluid, a piston in saidcylinder, there being a passage in said cylinder from one side to theother of the piston-head, connection between said piston and the drum,and mechanism operated by said drum, at predetermined points in itsrevolution to cause said piston to travel in said cylinder and graduallycut off said passage, and means to cause said piston to return to itsnormal position, substantially as described.

11. In an' elevator operated by a windingdrum, the combination with thedrum, of a cylinder adapted to contain a fluid, a piston in saidcylinder, there being a passage in said cylinder from one side to theother of the piston-head, an arm, one end connected with said piston,mechanism adapted to be operated by said drum at predetermined points inits revolution to move said arm and the piston in the cylinder andgradually cut off said passage, substantially as described.

12. In an elevator operated by a Windingdrum, the combination with thedrum, of a cylinder adapted to contain a fluid, a piston in saidcylinder, there being a passage in said cylinder from one side to theother of the piston-head, an arm one end connected with said piston andmechanism adapted to be operated by said drum, at predetermined pointsin its revolution, to move said arm and the piston in the cylinder andgradually cut off said passage, and means to cause said piston to returnto its normal position.

13. In an elevator, the combination with the elevator-hoisting mechanismof a cylinder adapted to contain a fluid, a piston in said cylinder,there being a passage from one side to the other of said piston, andmechanism intermediate of the piston and the hoisting mechanism adaptedto be operated at predetermined points in the operation of the hoistingmechanism and cause said piston to travel in said cylinder and graduallycut 0ft said passage.

In testimony of which invention I have hereunto set my hand.

FRANK E. TIERDMAN.

Witnesses:

WM. N. DUNNINGTON, CHAS. A. SUFFRINS.

